1. Field of the Invention
The present invention relates to supply chain management, and particularly to a system and method for a manufacturer or a product or service supplier to plan and manage its capacity so as to serve its customers' demands in the field of supply chain management.
2. Description of the Related Art
In the supply of products, the supply chain performs the functions of purchase of materials, transformation of these materials into intermediate and finished products, and distribution of these finished products to customers. The supply of services is in many ways similar to the supply of products. In the supply chain, customers transmit requests (or demands) that may include a request for a particular quantity of a product to a supplier by a specific date. The supplier plans its internal or external manufacturing schedule according to these received requests to satisfy each customer.
To strengthen competitive ability, supply chain management (or the management of supply chain functions and operations) has become an important issue to meet the goals of reduced inventory and increased productivity. Manufacturing and distribution facilities have limited resources and capacity. That is, not every customer request may be met, in that some may be promised but unfulfilled, some may get inadequate supply, and others may be rejected. Consequently, effective management (of both demand and capacity) in supply chain management, without excess capacity loss, has become an important aspect for a product or service supplier who needs to control manufacture or distribution.
The complexity of the supply chain may vary greatly from industry to industry and firm to firm. For a supplier whose business model involves long manufacturing cycle time but accurate time-to-delivery, high equipment cost, and high product value, demand and capacity management is even more critical. Integrated circuit (IC) foundry is such a business which needs to serve multiple customers with a wide spectrum of products, while the manufacturing process for a given product can not start before an order is given. Therefore, an IC foundry is facing a more difficult situation in its supply chain management.
In conventional methods, the supply chain management is used to manage and control related materials used in manufacturing steps. For example, U.S. Pat. No. 6,477,660 discloses a system for supply chain planning that manages material using a specified data model. However, this method is not suitable for a business in which the materials are not the key factor of supply chain management. Sometimes it may be more important to manage equipment (either manufacturing or distribution) utilization rate (as opposed to materials) for better capacity management.
Further, conventionally, demand and capacity management is often based on quantity. For example, the system and method for managing available to promised product of U.S. Pat. No. 6,188,989 manages capacity by quantity. By such conventional quantity-based method, the capacity of an IC foundry is represented by the quantity of wafers available to promise customers. However, the manufacturing process of an IC product may involve several tools and hundreds of steps, while an advanced IC product (such as a 0.13 um CPU) may need even more than double cycle time, mask cost and equipment cost of that of a much less advanced IC product (such as a 0.35 um game ROM). Thus, it can be readily seen that one 8-inch wafer for 0.13 um products is not at all equivalent to one 8-inch wafer for 0.35 um products, and it would not be reliable or accurate to measure capacity requirement by wafer quantity.
Consequently, the desired results of the conventional supply chain management tools are often not achievable or cannot be realistically implemented in an IC foundry or a business having a similar business model. There is no existing effective mechanism for demand and capacity management that is ideally suited for industries like IC foundries, and further no total solution is specially designed and proposed for supply chain management in such industries.
In addition, to achieve precise supply chain management, both customer and foundry requirements should be thoroughly considered. In most cases, the relationship between a customer and a foundry is not long-term one-to-one relationship. The customer does not promise to order, and the foundry does not promise to retain capacity.
From customer's perspective, wafer costs are high, while a product is not a staple material, in that the product may have only a short life cycle and soon be volatile. Consequently, delivery date and quantity management are critical in reducing customer's costs.
Generally, customers desire to control delivery date and quantity through planning and forecasting. Customers also wish the foundry (supplier) to become their virtual factory so as to lower the impact of marketing fluctuations, and reduce the cost of maintaining capacity. This naturally leads to overestimation of the demand by customers in order to book the capacity, and the foundry (supplier) consequently frequently over-commits in order to reduce order and capacity loss. This “distrust” between the customer and the foundry has become a major problem in supply chain management. Therefore, balancing and satisfying all customers, without losing capacity is a key challenge to supply chain management in the semiconductor industry.